Choosing a Password

Your passwords are the keys to many things: your bank machine, your computer, your email, a server on a network. Your password helps to prove you are who you say you are, and ensures your privacy. Compromised passwords are the means by which most unauthorized (and devious) people gain access to a system. Someone logging on under your name has access not only to your computer files, but to most of the facilities of the computer system. Since tampering can have far-reaching and serious consequences, it's important to take to heart the following guidelines for choosing a password. How would you lock the front door of your home? With a luggage lock or with a deadbolt?

Never tell anyone your password – not your friends, colleagues, account manager or even your system administrator or Helpdesk -- and don't write it down. Make sure you have chosen a password that you can remember. When you are given a new account, immediately change your password to one that only you know.

General Password Selection GuidelinesExpand

You want to choose something that is easy to remember with a minimum of 8 characters that uses as many of the techniques above as possible. One way to do this is to pick a phrase you will remember, pick all the first or last letters from each word and then substitute some letters with numbers and symbols. You can then apply capitals to some letters (perhaps the first and last, or second to last, etc.) You could also perhaps keep or add punctuation.

Some examples:

Phrase

First Letters

Password

"So long and thanks for all the fish”

slatfatf

5L@tf@tF

“Best Series Ever: Terry Goodkind’s Sword of Truth”

bsetgsot

B53:tg’Sot

“You Can't Have Everything. Where Would You Put It?”

ychewwypi

Uch3Wwup1?

If you are selecting a password for a website, you may want to incorporate the first few letters of the website name into your password so that every password is different and if one gets out, you don’t have to change them all. This approach has good and bad points.

For example, if you have a standard password like B53:tg’Sot (see above) that you like to use most places (this not recommended), you may modify it by placing the first and last letter of the website around it:

Why do I need a complex password?Expand

If you only use words from a dictionary or a purely numeric password, a hacker only has to try a limited list of possibilities. A hacking program can try the full set in under one minute. If you use the full set of characters and the techniques above, you force a hacker to continue trying every possible combination to find yours. If we assume that the password is 8 characters long, this table shows how many times a hacker may have to before guessing your password. Most password crackers have rules that can try millions of word variants per second, so the more algorithmically complex your password, the better.

The longer your password the more secure. If we take the full set of allowed printable characters set (the last line above) and increase the password length, the possible combinations jump exponentially (odd, considering that the calculation includes exponents...)